Three decades of hematologic cell culture research have led to clear identification of BLOOD forming progenitors and their proliferation and differentiation factors (collectively called hormones in this proposal). As a consequence, many BLOOD disorders are understood and, through molecular technology, it is increasingly possible to treat red cell and white cell deficiencies with recombinant hormones. Of particular relevance here is the recent recognition by scientists of the role of hormones in the proliferation of leukemia cells. While the therapeutic implications are most exciting, The hormone-receptor axis should yield new assays for detection and diagnosis of leukemia. The first step in exploiting hormone sensitivity for patient care is to determine which hormones support growth of which patient's cells. Unfortunately since current assays are available only in highly specialized research labs, few patients actually benefit from this potentially valuable hormone- response data. Chi Associates had assembled a highly experienced team of academic investigators to develop a prestandarized, easy to use kit which will reliably asses hormone sensitivity of leukemia samples. Through uniformly successful Phase I studies, this team has a already proven the feasibility and utility in animal models. They now propose to extend and standardize these hematological assays for use with human leukemia samples. When successful, the widespread use of such assays could lead to new hormone-related therapies, and the clinical assays should lead to better detection, diagnosis and monitoring of leukemias, discoveries of new hormones, and in vitro tests for drug efficacy.